---
title: "Multiple RRs of singleton type and CNAME and other data errors"
slug: "aa-00297"
description: "These indicate a malformed master zone."
updated: 2018-10-26T16:53:59Z
published: 2018-10-26T16:53:59Z
canonical: "kb.isc.org/aa-00297"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.isc.org/llms.txt
> Use this file to discover all available pages before exploring further.

# I get error messages like "multiple RRs of singleton type" and "CNAME and other data" when transferring a zone?

These indicate a malformed master zone. You can identify the exact records involved by transferring the zone using `dig`, then running `named-checkzone` on it.

```
CHARSET=ASCII IDN_DISABLE=1 dig +onesoa axfr example.com @master-server > tmp

named-checkzone example.com tmp
```

A CNAME record cannot exist with the same owner name as another record except for its RRSIG and the DNSSEC records which prove non-existence of other records (NSEC).

RFC 1034, Section 3.6.2 states: "If a CNAME RR is present at a node, no other data should be present; this ensures that the data for a canonical name and its aliases cannot be different. This rule also insures that a cached CNAME can be used without checking with an authoritative server for other RR types."